Phase change material compositions and methods for their use to lower surface friction and wear

Abstract

Phase change material compositions and methods for using the compositions to prepare substrate coatings or bulk blended polymers that advantageously lower friction between interacting substrate surfaces and lower substrate surface wear.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A method for coating a substrate to enhance the tribological and mechanical performance of a coating, comprising coating a surface of the substrate with a phase change material composition,
 wherein the phase change material composition is a combination of a phase change material and a polymeric material, and 
 wherein the polymeric material is an aromatic thermosetting copolyester. 
 
     
     
       2. The method of  claim 1 , wherein the phase change material composition is a phase change material coated on the polymeric. 
     
     
       3. The method of  claim 2 , wherein the phase change material forms a film on the polymeric. 
     
     
       4. The method of  claim 2  further comprising heating the phase change material coated on the polymeric material to provide a coating wherein the phase change material is infused into the polymeric material. 
     
     
       5. The method of  claim 1 , wherein the phase change material is selected from the group consisting of organic, inorganic, and eutectic phase change materials. 
     
     
       6. The method of  claim 1 , wherein the phase change material is a paraffin. 
     
     
       7. The method of  claim 1 , wherein the phase change material is a paraffin having a melting point from about 40° C. to about 65° C. 
     
     
       8. The method of  claim 2 , wherein the combination of the phase change material and the polymeric material comprises from about 2 to about 20 percent by weight phase change material. 
     
     
       9. The method of  claim 1 , wherein the phase change material composition is a phase change material encapsulated in an encapsulating polymer. 
     
     
       10. The method of  claim 9 , wherein the phase change material is a paraffin. 
     
     
       11. The method of  claim 9 , wherein the phase change material is n-docosane or n-tricosane. 
     
     
       12. The method of  claim 9 , wherein the encapsulating polymer is a melamine-formaldehyde polymer, a polyurea-formaldehyde polymer, a polymethylmethacrylate polymer, or mixtures thereof. 
     
     
       13. The method of  claim 2 , wherein the coating is formed from a powdered phase change material and a powdered polymeric material. 
     
     
       14. The method of  claim 2 , wherein the coating has a thickness from about 35 μm to about 1 mm. 
     
     
       15. The method of  claim 1 , wherein the substrate is a polymeric substrate, a metallic substrate, a metal alloy substrate, or a ceramic substrate. 
     
     
       16. The method of  claim 1 , wherein the substrate is a stainless steel substrate. 
     
     
       17. A substrate having a surface coated with a phase change material prepared by the method of  claim 1 .